1 | /****************************************************************************** |
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2 | * This function receives two arguments that are the current thread context |
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3 | * (virtual) addresses and the next thread context (virtual) address. |
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4 | * |
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5 | * This function should be called in a critical section |
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6 | * |
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7 | * TODO (AG) Il semble possible de limiter le nombre de registres à sauver: |
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8 | * - s0 Ã s8 ($16 Ã $23 + $30) |
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9 | * - sp ($29) |
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10 | * - ra ($31) |
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11 | * - hi et lo |
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12 | * - sr |
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13 | * - epc |
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14 | * - ptpr |
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15 | ******************************************************************************/ |
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16 | |
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17 | .globl _thread_switch |
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18 | .func _thread_switch |
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19 | .type _thread_switch, %function |
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20 | |
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21 | _thread_switch: |
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22 | |
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23 | /* first step : save current thread context */ |
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24 | add $27, $4, $0 /* $27 <= &context[current] */ |
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25 | |
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26 | .set noat |
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27 | sw $1, 1*4($27) /* ctx[1] <= $1 */ |
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28 | .set at |
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29 | sw $2, 2*4($27) /* ctx[2] <= $2 */ |
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30 | sw $3, 3*4($27) /* ctx[3] <= $3 */ |
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31 | sw $4, 4*4($27) /* ctx[4] <= $4 */ |
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32 | sw $5, 5*4($27) /* ctx[5] <= $5 */ |
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33 | sw $6, 6*4($27) /* ctx[6] <= $6 */ |
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34 | sw $7, 7*4($27) /* ctx[7] <= $7 */ |
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35 | sw $8, 8*4($27) /* ctx[8] <= $8 */ |
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36 | sw $9, 9*4($27) /* ctx[9] <= $9 */ |
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37 | sw $10, 10*4($27) /* ctx[10] <= $10 */ |
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38 | sw $11, 11*4($27) /* ctx[11] <= $11 */ |
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39 | sw $12, 12*4($27) /* ctx[12] <= $12 */ |
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40 | sw $13, 13*4($27) /* ctx[13] <= $13 */ |
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41 | sw $14, 14*4($27) /* ctx[14] <= $14 */ |
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42 | sw $15, 15*4($27) /* ctx[15] <= $15 */ |
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43 | sw $16, 16*4($27) /* ctx[16] <= $16 */ |
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44 | sw $17, 17*4($27) /* ctx[17] <= $17 */ |
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45 | sw $18, 18*4($27) /* ctx[18] <= $18 */ |
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46 | sw $19, 19*4($27) /* ctx[19] <= $19 */ |
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47 | sw $20, 20*4($27) /* ctx[20] <= $20 */ |
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48 | sw $21, 21*4($27) /* ctx[21] <= $21 */ |
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49 | sw $22, 22*4($27) /* ctx[22] <= $22 */ |
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50 | sw $23, 23*4($27) /* ctx[23] <= $23 */ |
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51 | sw $24, 24*4($27) /* ctx[24] <= $24 */ |
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52 | sw $25, 25*4($27) /* ctx[25] <= $25 */ |
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53 | mflo $26 |
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54 | sw $26, 26*4($27) /* ctx[26] <= LO */ |
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55 | mfhi $26 |
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56 | sw $26, 27*4($27) /* ctx[27] <= H1 */ |
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57 | sw $28, 28*4($27) /* ctx[28] <= $28 */ |
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58 | sw $29, 29*4($27) /* ctx[29] <= $29 */ |
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59 | sw $30, 30*4($27) /* ctx[30] <= $30 */ |
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60 | sw $31, 31*4($27) /* ctx[31] <= $31 */ |
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61 | mfc0 $26, $14 |
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62 | sw $26, 32*4($27) /* ctx[32] <= EPC */ |
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63 | mfc0 $26, $13 |
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64 | sw $26, 33*4($27) /* ctx[33] <= CR */ |
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65 | mfc0 $26, $12 |
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66 | sw $26, 34*4($27) /* ctx[34] <= SR */ |
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67 | mfc0 $26, $8 |
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68 | sw $26, 35*4($27) /* ctx[34] <= BVAR */ |
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69 | mfc2 $26, $0 |
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70 | sw $26, 39*4($27) /* ctx[35] <= PTPR */ |
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71 | |
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72 | /* second step : restore next thread context */ |
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73 | add $27, $5, $0 /* $27<= &context[next] */ |
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74 | |
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75 | .set noat |
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76 | lw $1, 1*4($27) /* restore $1 */ |
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77 | .set at |
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78 | lw $2, 2*4($27) /* restore $2 */ |
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79 | lw $3, 3*4($27) /* restore $3 */ |
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80 | lw $4, 4*4($27) /* restore $4 */ |
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81 | lw $5, 5*4($27) /* restore $5 */ |
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82 | lw $6, 6*4($27) /* restore $6 */ |
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83 | lw $7, 7*4($27) /* restore $7 */ |
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84 | lw $8, 8*4($27) /* restore $8 */ |
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85 | lw $9, 9*4($27) /* restore $9 */ |
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86 | lw $10, 10*4($27) /* restore $10 */ |
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87 | lw $11, 11*4($27) /* restore $11 */ |
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88 | lw $12, 12*4($27) /* restore $12 */ |
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89 | lw $13, 13*4($27) /* restore $13 */ |
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90 | lw $14, 14*4($27) /* restore $14 */ |
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91 | lw $15, 15*4($27) /* restore $15 */ |
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92 | lw $16, 16*4($27) /* restore $16 */ |
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93 | lw $17, 17*4($27) /* restore $17 */ |
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94 | lw $18, 18*4($27) /* restore $18 */ |
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95 | lw $19, 19*4($27) /* restore $19 */ |
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96 | lw $20, 20*4($27) /* restore $20 */ |
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97 | lw $21, 21*4($27) /* restore $21 */ |
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98 | lw $22, 22*4($27) /* restore $22 */ |
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99 | lw $23, 23*4($27) /* restore $23 */ |
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100 | lw $24, 24*4($27) /* restore $24 */ |
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101 | lw $25, 25*4($27) /* restore $25 */ |
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102 | lw $26, 26*4($27) |
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103 | mtlo $26 /* restore LO */ |
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104 | lw $26, 27*4($27) |
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105 | mthi $26 /* restore HI */ |
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106 | lw $28, 28*4($27) /* restore $28 */ |
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107 | lw $29, 29*4($27) /* restore $29 */ |
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108 | lw $30, 30*4($27) /* restore $30 */ |
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109 | lw $31, 31*4($27) /* restore $31 */ |
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110 | lw $26, 32*4($27) |
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111 | mtc0 $26, $14 /* restore EPC */ |
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112 | lw $26, 33*4($27) |
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113 | mtc0 $26, $13 /* restore CR */ |
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114 | lw $26, 34*4($27) |
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115 | mtc0 $26, $12 /* restore SR */ |
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116 | lw $26, 35*4($27) |
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117 | mtc0 $26, $8 /* restore BVAR */ |
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118 | lw $26, 39*4($27) |
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119 | mtc2 $26, $0 /* restore PTPR */ |
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120 | |
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121 | /* returns to caller */ |
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122 | jr $31 |
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123 | |
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124 | .endfunc |
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125 | .size _thread_switch, .-_thread_switch |
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126 | |
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